Art or method of producing oxygen and nitrogen.



M. HAZARD-FLAMAND.

ART 0R METHOD OF PRODUCING OXYGEN AND NHROGEN.

APPLICATION FILED DEC. 31! l9l5.

Patented Oct. 10, 1916.

ygaw UNITED STATES PATENT OFFICE,

MAURICE HAZARD-FLAMAND, OF ST. YRAIN, FBANCE."

ART OB METHOD OF PRODUCING OXYGEN NITROGEN.

Specification of Letters I'ateht. Patented Oct. 10, 1916.

Original application filed December 9, 1908, Serial No. 468,683. Divided and this application filed December 31, 1915. Serial No. 69,700.

To all whom it may concern:

Be it known that I, MAURICE HAZARD- F AMAND, a citizenof. the Republic of France, residing at St. Vrain, Seine-et-Oise, France, have invented certain new and useful Improvements in the Art or Method of Producing Oxygen and Nitrogen, of which the following isa specification, reference being had therein to the accompanying drawings, which form a part thereof.

My invention relates to the art or method of producing oxygen and nitrogen and more particularly to the art or method capable of being practised in the apparatus described and claimed in my application for Letters Patent, filed in the United States Patent Oflice, upon the 9th day of December, 1908, Serial" No. 466,683, of which application this is a division. a

By my invention, I am enabled to produce oxygen and nitrogen from air by a fractional distillation process, the practice of which does not require the air to be liquefied before treatment. By this method, I separate the nitrogen and the oxygen under conditions which will insure substantially pure gases, approximating in volume the percentage of each gas contained in theair subjected to. the treatment. a

My improved art or method utilizes nitrogen, at a pressure and a temperature which will liquefy oxygen, as the means for effecting the separation of the constituents of the air and hen'cea portion of the products secured by the practice of mymethod, may be utilized. in a continuance of the practice and not only admit of a continuous method of separating the gases of the air,

but an economical method as well.

My improved method requires the maintenance of very low temperatures during all steps thereof, and in the practice of the invention, I arrange to abstract from the .air to be subjected to thetreatment' as higha percentage of the heat units as is practicable practice of my method,

ering the temperature of the air to the tember with the incidental vaporization of' said oxygen. I

he invention consists primarily in the art or method of producmg oxygen and nitrogen consisting in subjecting the air at substantially the temperature of its sat- -urated vapors to the action of nitrogen at a temperature and pressure at which oxygen will liquefy whereby the oxygen will be liquefied and the nitrogen will be released therefrom in gaseous form, and in such other novel steps and practices as are hereinafter set forth and described and more particularly pointed out in the claims hereto appended. i

In the accompanying drawings I have shown one form of apparatus suitable for use in practising my art or method and will describe my art or method in connection therewith, it not being my intention to limit theinvention to any particular apparatus.

In the practice of the art or method of my invention, I deliver-air to adistilling column or chamber at the temperature of its saturated vapors, which is about 190 C. and at substantially atmos heric pressure. As this vapor enters the di'st' ing column or chamberit is subjected. to} the action of nitrogen at a temperature and pressure 4 which will liquefy the oxygen contained in said vapor, as the mixture travels from stage to stage of the column of the rectifier, thus' separating the nitrogen of said vapor from the oxygen, causing the oxygen to eventually fall as a liquid to the bottom of the column and the nitrogen to eventually-rise. to the 1 top of the column as a In practice, I have found that liquid mtrogen'may be successfully used in securing this separa-. 'tion of the vapors.

The foregoing methodof separating the oxygen and nitrogen is a predominant characteristic of myinvention, other steps being those incidental to preparing the air for introduction to the distilling 'column or chamber; vaporizing and removing the liquid oxygen accumulated in the bottom of the column; and developing the required 35 column is piped through the exchanger low temperature and pressure of the nitrogen used in effecting the separation of the nitrogen and-oxygen.

In the initial stages of the practice of my art or method, it is essential to reduce the air to the temperature of its saturated vapors, which may be done in any desired manner and by any desired means, and also to use nitrogen at the desired temperature and pressure which may be procured in any desired manner. After the initial stages, however, my art or method will condition the air to be introduced to the distilling column and produce the nitrogen required in the separating step, the conditioning of the air having as an incident thereto the conservation of a high percentage of the cold developed in the practice of the invention.

Assumingv that air is being separated in the manner above referred to, gaseous nitrogen constantly ascends toward the upper portion of the distilling column, and is withdrawn therefrom, in any desired manner, as by means of a compressor, and passed by the compressor through a refrigerator and thence through heat exchangers to expansion tubes in an expansion chamber and to a condensing chamber from which it is drawn when at the requisite temperature 1 and pressure and delivered to the upper portion of the distilling column for the purpose of continuing the process in connection with a continuous flow of the saturated vapors of the air. Hence I have a continuous circulation of the nitrogen, beginning with a gaseous form in the distilling column. Said nitrogen in the course of its circulation from the compressor gives up heat units to the nit'rogenfiowing from the dis tilling column; and to the oxygen being delivered; and takes up heat units from the air whereby in conjunction with the expansion thereof, such air is brought to the temperature ofits saturated vapors. Finally said nitrogen through its boiling ac- ,tion upon the liquid oxygen and the pressure exerted upon it, is converted from a gaseous to a liquid form. A portion only of the nitrogen withdrawn from the distilling column is ,used in continuing the process, the balance thereof, which is pure nitrogen, being one of the products secured by the practice of my invention. The low temperature in one of the heat exchangers is maintained by means of the gaseous nitrogen withdrawn from the distilling column while the low temperature of the other heat exchanger is maintained by the nitrogen being piped therethrough and the gaseous oxygen beiaiig passed through the exchanger about the pipe through which the nitrogen is flowing. I

e air to be introduced to the distilling through which the gaseous nitrogen flows in passing from the distilling column, the pressure of the air and its temperature at this stage, being such that when it is expanded inthe expansion chamber above referred to, such expansion in conjunction with the refrigerating or expansion tubes through which the nitrogen passes, will lower the temperature of said air to that of its satthe vapors being introduced thereto.

The liquid oxygen accumulated in the bottom of the distilling column is preferably separated into two bodies both of which are subjected to the action of the nitrogen in the condensing chamber, the three-fold results secured being the liquefaction of the nitrogen; the vaporization of aportion of r the oxygen constituting one of the products secured by the practice of my invention; and the development of oxygen vapors within the distilling column which as they rise in said column will assist in the distillation of the nitrogen contained in the colunm. By continuously withdrawing the liquid oxygen from the boiler at the bottom of the distilling column and delivering it to the vaporizer by means of which a division of the said oxygen is effected, I am enabled to secure a pure oxygen gas, and retain in the columns sufiicient liquid oxygen to insure the proper conditions within the column and the continuance of the distillation I process.

The liquid nitrogen delivered" to the distilling column or chamber, in its descent, not only separates the vaporized air into its constituents but is in its turn vaporized ,by the ascending oxygen vapors which as a result of the distillation process continuing in said column, are again condensed or liquefied and re-delivered to the boiler therefor at the bottom of the column. By separating the liquefied oxygen into two separate bodies,'.

I am enabledto liquefy the desired volume of nitrogen preparatory to its delivery to the distilling column and at the same time vaporize a sufficient volume of oxygen for use in the workof distillation in the column and I 129% volumes of nitrogen and approximately- 34.4 volumes of oxygen.

Incidental to the conditioning of the air preparatory to its delivery to the distilling column, carbonic acid gas and other iinpuri-' be used in thepractice of my invention, I

have shown in the accompanying drawings an apparatus suitable for such use in which drawings, (4 indicates a multiple stage distilling column, b the nitrogen oif-take pipe, 0 a heat interchanger constituting a portion of said ofi-take pipe, and d the off-take outits let for the nitrogen gas as a product. Connected with the pipe?) 'is' a compressor or pump 6, the'other lead of which delivers nitrogen to a'refrigerating coil g. Beyond the coil g. the nitrogen is conveyed through a pipe 11. having two branches h If, one of which as It passes through the heat exchanger c and the other ofwhich passes through a second heat interchanger which will be referred to hereinafter. The said branches unite below said heat exchanger and discharge into a set of refrigerating tubes 12. arranged in an expansion chamber z'and provided with expansion headers as shown. The bottom of the distilling column a is provided with a boiler a surrounding and in connection with-which, as by means of the siphon tube. a is a vaporizer u Below the boiler 21' and vaporizer a is a condensing chamber is. into which the nitrogen after leaving the refrigerating tubes is is discharged through the pipe 7'. Leading from the lower portion ofthe condensing chamberlc is a pipe m discharging into the upper portionof the distilling column having in 1ts length an expansion valve m, the nitrogen being conveyed at the proper temperature and pressure from the chamber to the upper portion of the column through said pipe. Leading from the vaporizer a is an oxygen oflf-take pipem. in'length of which is a heat exchanger 0 through which the branch k of the mtrogen pipe system passes, the oxygen being withdrawn beyond 'said exchanger through the off-take p. The air to be treated is admitted to the expansion chamber 6 by meansof the pipe 9, the said pipe being provided in its length with an expansion valve- 9' adjacent said chamber. The chamber a connects with the distilling column through the duct 7.

.It will be apparent from the foregoing,

description that .by maintaining a continuous circulation 'of the nitrogen, the art or method will be a continuous one.

Having described the invention, what I claim as new and desire to have protected by Letters Patent isz- 1. The'art or method of producing oxygen and nitrogen consisting in subjecting air at substantially the temperature of its saturated vapors to the-action of nitrogen at a temperature and a pressure at which oxygen will liquefy whereby the oxygen will be liquefied and the nitrogen will be separated therefrom in gaseous form.

'2. The art or method of producing oxygen and nitrogen consisting in subjecting air at substantially the temperature of its saturated vapors to the action of liquidnitrogen whereby the oxygen will be liquefied and the nitrogen will be separated therefrom in gaseous form.

3. The art or method of producing oxygen and nitrogen consisting in subjectingair at substantially the temperature of its saturated vapors to the action of nitrogen at a temperature and a pressure at which oxygen will liquefy-and to the action of vaporized oxygenwherebythe oxygen in the air will be liquefied and the nitrogen will be separated therefrom in gaseous form;

4. The art or method of producing oxygen and nitrogen consisting inintroducing air to a distilling column at' substantially the temperature of its saturated vapors and subjecting said air to the action of a descending column of liquid nitrogen and an ascending column of vaporized oxygen.

'5. The art or method of producing oxygen and nitrogen consisting in introducing air into a distilling column atsubstantially the temperature of its saturated vapors, subjecting said air to the action of nitrogen at a temperature and pressure at which oxygen will liquefy, collecting the liquefied oxygen in a boiler at the bottom of the distilling column, withdrawing the nitrogen gases from the upper part of the column, condensing said gases by boiling the liquefied oxygen therewith,v and re-delivering the condensed gases tothe distilling column whereby the oxygen in said vaporized air will be continuously liquefied and the nitrogen will be continuously separated therefrom in gaseous form to the upper part'of said column.

6. The art or method of producing oxygen and nitrogen consisting in introducing air at substantially the temperature of its saturated vapors into'a distilling column at a point thereof where the temperature will be substantially that of said vapors, subjecting said air to the action of mtrogen at a temperature and pressure at which oxygen will liquefy, collecting the liquefied oxygen in a boiler at the bottom of the distilling,

column, withdrawing the nitrogen gases .from the upper part of the. column,'condensing said gases by boiling the liquefied oxygen therewith, and re-delivering the condensed gases to the distilling column whereby the'oxygen in said vaporized air will be continuously liquefied and the nitrogen will be continuously separated therefrom in gase ous form to the upper part of said column.

7. The art or method of producing oxygen and nitrogen consisting in subjecting air at substantially the temperature of its saturated vapors to the -action of nitrogen at a temperature and a pressure at which oxygen will liquefy whereby the oxygen will be liquefied and the nitrogen will be separated therefrom in gaseous form, subjecting the airto be treated to a gaseous nitrogen and expanding said air in a refrigerating expansion chamber whereby it will be brought to the desired temperature and-to atmospheric pressure. p

8. The art or method of producing oxy gen and nitrogen consisting in introducing air. into a distilling column at substantially the temperature of its saturated vapors, subjecting said air to the action ofthe nitrogen at a temperature and pressure at which oxygen will liquefy, collecting the liquid oxygen in a boiler at the bottom of the distilling column, dividing the body of said oxygen into'two parts, condensing said nitrogen gases by boiling the liquefied oxygen 'in both parts of the body thereof, maintaining a continuous circulation of nitrogen by withdrawing it from the upper portion of said column in the form of gas passing it about said boiler and re-delivering it in its condensed or liquefiedform to the upper portion of said distilling column, bringing the air to be introduced into said column to the desired temperature by causing the absorption of the heat units therein by said nitrogen in the course of its circulation and expanding said air in an expansion chamber, refrigerated by means of said nitrogen during the circulation.

9. The art or method of producing oxygen and nitrogen consisting in introducing air into a distilling column at substantially the temperature of its saturated vapors, subjecting said air to the action of the nitrogen at a temperature and pressure at which oxygen will liquefy, collecting the liquid oxygen in a boiler at the bottom of the distilling column, dividing the body of said oxygen into two parts,'condensin-g said ni trogen gases by boiling theliquefied oxygen in both parts of the body thereof, maintaining a continuous circulation of nitrogen by withdrawing it from the upper portion of said column in the form of gas passing it about said boiler and re-delivering it in its condensed or liquefied form to the upper portion of said distillin column, bringing the air to be introduced into said column to the desired temperature by causing the absorption of the heat units therein by. said nitrogen in the course of its circulation and expanding said air in an expansion chamber, and expanding said nitrogen in the course of its circulation in said expansion chamber.

- 10. The art or method of producing oxygen and nitrogen consisting in introducing nitrogen at a temperature and pressure at which oxygen will liquefy, upon the upper stages of a distilling column, forming oxygen vapors below the lower stages and Within said column, introducing air at substantially the temperature of its saturated vapors at a stage intermediate the top and bottom of said column where the temperatures are substantially those of the saturated vapors, withdrawing gaseous nitrogen from the upper part of said column, vaporizing a part of the liquid oxygen and withdrawing such vapors from without said column.

In witness whereof I hereunto affix my signature in the presence of two subscribing witnesses.

MAURICE HAZARD-FLAMAND.

' Witnesses:

I. C. DOUMEY, DE Wrr'r O. POOLE, Jr. 

